This seems to be freedesktop.org bug #64858: https://bugs.freedesktop.org/show_bug.cgi?id=64858
** Bug watch added: freedesktop.org Bugzilla #64858 https://bugs.freedesktop.org/show_bug.cgi?id=64858 -- You received this bug notification because you are a member of Desktop Packages, which is subscribed to xserver-xorg-video-nouveau in Ubuntu. https://bugs.launchpad.net/bugs/1182051 Title: Turning off eDP-1 causes stutter Status in “xserver-xorg-video-nouveau” package in Ubuntu: New Bug description: After upgrading to Raring, my X stutters a lot whenever the eDP-1 output is disabled (for example with xrandr). In this state, the kernel log is also filled with numerous messages regarding invalid EDID checksums. The behavior was not seen with Quantal. The problem also partially goes away with mainline kernel 3.9. I would describe the stutters as about 10 ms freezes occurring roughly every second. Meanwhile, dmesg sees a lot of "[drm:drm_edid_block_valid] *ERROR* EDID checksum is invalid, remainder is 48" and a few "nouveau E[ I2C][0000:01:00.0] AUXCH(1): tx req timeout 0x01114000". Behavior is restored to normal when eDP-1 is re-enabled. The problem was not seen in Quantal. Installing the 3.9 mainline kernel partially mitigates the problem, but brings other ones, such as a kworker thread pegged at 100% CPU. This could be unrelated. The drm_kms_helper.poll=0 boot parameter does not help with the standard Raring kernel, but is in fact neccessary with 3.9. The problem seems to be unrelated to whether or not there are multiple monitors attached, for example on DP-1 and VGA-1. A single monitor on either DP-1 or VGA-1 is enough to observe the stutter as soon as eDP-1 is disabled. (Simply leaving eDP-1 enabled is not an option for me, as it has to be disabled to use DP-1 and VGA-1 simultaneously on my laptop.) Ubuntu version: 13.04 xserver-xorg-video-nouveau version: 1:1.0.7-0ubuntu1 Kernel version: 3.8.0-21.32 Graphics hardware: 01:00.0 VGA compatible controller: NVIDIA Corporation GT218M [NVS 3100M] (rev a2) To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/xserver-xorg-video-nouveau/+bug/1182051/+subscriptions -- Mailing list: https://launchpad.net/~desktop-packages Post to : desktop-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~desktop-packages More help : https://help.launchpad.net/ListHelp
